Sounds like your are trying to pass an exam. Perhaps you need to figure these out on your own. A little self study goes a long way ..
"Satisfaction does not come from knowing the solution, it comes from knowing why." - Rosalind Franklin
"I'm in a serious relationship with my Wi-Fi. You could say we have a connection."
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What "kind" of links interconnect switches 1, 2 and 3? (I.e. how are the interconnecting ports configured?)